1. What is the difference between Aramid and Polyester Fabric?

Aramid fabric is a unique high temperature resistant material that performs well under heat. This material has been used for decades in firefighter turnout gear and racing suits. It is more commonly known by trade names such as Nomex® or Konex®. Aramid has a maximum sustained temperature range of 500°F and remains flexible in sub-zero temperatures. We utilize 4 plies of Aramid fabric reinforcing layers in all of our Verocious Motorsports silicone hoses for direct turbo installations.

Polyester is probably the most common reinforcing material for silicone hoses. Polyester reinforced hoses are suitable for intakes, intercooler plumbing, and coolant hoses. Polyester reinforced hoses have a continuous temperature range from -65°F to 350°F.

Summarily, we suggest that you use a 4 ply Aramid coupler or reducer for direct turbo/supercharger installations, and our polyester reinforced hoses for all your other plumbing connections. This gives you the security of knowing that you have the right type of coupler mounted to the turbo and provides a more cost effective package by utilizing the polyester reinforced hoses downstream where it is cooler.

2. How does your Aramid reinforced hose stand up to fiberglass reinforced hose?

With a maximum temperature range of only 50°F more than Aramid reinforced silicone hoses; we have found that using fiberglass as reinforcement doesn't make sense. Fiberglass is brittle, and not very flexible by nature. Additionally, in sub-zero climates fiberglass hoses can become stiff and split when subjected to engine movement.

Let's look at the heavy truck industry as an example. These trucks have been engineered to work 24 hours a day in all climates, from the deserts of the Southwest, to the frigid Canadian winters. 99% of these trucks utilize multi-layer Aramid fabric reinforcement on the hot side and multi-layer polyester reinforced hoses on the cold side of their turbo systems.

3. Does the number of reinforcing layers really matter?

We manufacture our hose to the SAE J20 RI specification. If the Society of Automotive Engineers (SAE) didn't think it mattered, then we would not have a specification to follow. These engineers have determined what normal operating pressures and burst pressure should be for each size of hose. Furthermore the specification calls out the number of plies and the hose wall thickness required to be approved. Within the specification there are requirements for 3 and 4 ply hose, however no where in the specification does it say that a 1 or 2 ply hose is acceptable.

4. I have heard that 4 ply is hard to cut, is this true?

4 Ply reinforced hoses are no different to cut than 2 or 3 ply hoses. Silicone is inherently weak in its raw form. We use reinforcing layers to help produce a stronger hose. If you are purchasing long lengths of hose and need to cut them down to length upon installation, you will need the following tools:

• A liner clamp properly sized for the hose you intend to cut
• A tape measure
• A fresh razor blade utility knife (we suggest that you find the type of knife that utilizes the trapezoidal blades that are double sided). A brand new sharp blade is very important.
• Optional: Modified EasySeal clamp for 3" coupler template

You can view our write up on cleaning and cutting silicone hose for detailed instructions.

5. Are different colors on the inside and the outside of the hose a sign of poor construction?

This is actually a myth. The inside of the hose is called the "liner" and the outside the "cover" or "jacket". Some manufacturers utilize a two part manufacturing process where the liner is first extruded through a die to the correct size and partially cured to hold its shape during the final steps. The liner is then slid over a mandrel and the individual layers are then hand wrapped on top of the liner.

Since silicone is one of the easiest polymers to color, some manufacturers started using different colors to visually differentiate their products from other manufacturers. One company may utilize a flame red liner whereas another company may utilize an iron oxide (orange) liner. The 2 different colors are more of a fashion statement than a functional characteristic.

6. I have heard of 1000°F resistant silicone hoses, do you offer these?

If anybody tells you they have a 1000°F resistant silicone hose, I would politely thank them for their time and take my business elsewhere. The main silicone manufacturing companies will all give you the same information; there is NO SILICONE COMPOUND THAT CAN WITHSTAND 1000°F. The FAA conducted a test several years ago where a specific product had to be subjected to a 2000°F flame for two minutes without backside ignition or flame penetration. The test was a success and there was no penetration or backside ignition. However, the silicone seal was CONSUMED in the test as the ceramic fabric maintained the seals integrity. The front side of the silicone seat had actually turned into white ash by the time the two minutes had elapsed, yet the backside looked as fresh as when the test started.

Does that mean we have 2000°F resistant silicone? NO!

7. Does a longer transition/reducer have a higher flow rating?

The length of the hose does not control the flow characteristics. We too have read about several companies stating that their 4" and 5" long reducers flow better than a 3" long reducer. In order to prove this we need to know the anatomy of a reducer. The flat section on the reducer where the clamps are positioned is called the cuff. If we made each cuff 5" long and made the reducers over all length 12" would this flow better? NO! Turbulence cannot be caused by the angle at which the transition from one size to the other is made.

8. What size T-bolts do I need?

Our Stainless Steel T-Bolt Clamps have been custom made for our hoses. A size chart is provided in the T-bolt clamp section of our online store. We have sized our T-bolts to provide a minimum amount of "tail" on the bolt for the cleanest look on your installation.

If you are not using our hoses there is a simple math calculation to decide which T-bolt best suits your application. Take the inside diameter of the hose (should be the same as the outside diameter of your tubing) and add two times the wall thickness to get the outside diameter of the hose. Look at our clamp selection and find the clamp with a range that fits the OD of your hose.

9. Is there a difference between platinum catalyzed vacuum hose and other vacuum hoses?

When silicone is in its raw state it is known to be "uncured". At this stage it is pretty much the consistency of Jell-O. In order for the silicone to take a shape it must be cured with a catalyst. The catalyst can be one of several different chemicals, but the two most commonly used are dichlorobenzoyl peroxide and platinum. The majority of the silicone hose you have seen for sale at the corner auto parts store is made with a peroxide curing system. Most manufacturers use this system for a couple of different reasons. The first of which is that it is much cheaper to produce. On average a peroxide system will cost about 40-50% less per pound than platinum. The second reason has to do with the manufacturing aspect of the silicone itself. Peroxide silicone has a mixed shelf life up to about six months, whereas a platinum silicone must be put into production within hours of mixing. This very short shelf life, accompanied with the higher cost of the silicone, can create a large amount of scrapped raw materials. Therefore it is much easier for manufacturers to make peroxide silicones.

Now here is where it is a benefit to you. Platinum silicones are far superior in physical properties over a peroxide system. In some cases you may see increases of up to 60% in tensile, elongation, and tear strength. Platinum silicones are less prone to kink or collapse. Because of the tighter cure, they always want to return to the original shape it was cured in (straight). That means when you want to run a vacuum line with a tight bend or corner to turn, you won't have to worry about Verocious Motorsports Platinum Cured Silicone Vacuum Hose collapsing on you. They are brilliantly colored, remain shiny and are easy to clean with alcohol.

10. Can your silicone vacuum hose be used in a fuel/oil environment?

Silicone has very poor resistance to fuel and oils. Silicone hoses should never be used as oil drain lines or fuel lines. Over time the silicone will swell and the physical properties will diminish to the point where the hose will fail. On certain vehicles like the Mazda RX7 there are a lot of aromatic hydrocarbons flowing through the vacuum lines. We have seen evidence of oil contamination in these lines where the silicone has actually swelled to the point where the hose crumbled.